1. Field of the Disclosure
This disclosure relates generally to the field of abrasive surface preparation, and more particularly to methods and apparatus for measuring the profile of a prepared surface.
2. Discussion of Related Art
Abrasive surface preparation is a process used to clean or condition the surface of a material, typically metal, to strengthen it, prepare it for receiving a coating, such as paint, or for other purposes. In one conventional technique, an abrasive media is blasted onto the surface under high pressure. The resulting profile of the prepared surface (i.e., the three-dimensional variations of the surface from a perfectly smooth or “true” plane) describes the relative roughness of the surface, and is known to be a factor in the performance of various coatings applied to metals, such as steel. One existing standard for quantifying surface irregularities is described by ANSI B46.1-2009: Surface Texture, Surface Roughness, Waviness and Lay (American Society of Mechanical Engineers, Aug. 20, 2010, ISBN 9780791832622).
Several known techniques for measuring surface profiles are described, for example, in ASTM International Book of Standards, Volume 06.02, Paint—Products and Applications; Protective Coatings; Pipeline Coatings, D4417 (Methods A, B and C). In ASTM D4417 Method A, a visual comparator (e.g., a template) is viewed in comparison with the surface being measured, usually with a magnifier. In Method B, a gauge having a needle or stylus is laid on top of the surface at various locations to measure the distance between the peaks and valleys of the surface. In Method C, a tape having a compressible foam layer is pressed onto a portion of the surface to make an impression of the profile, which is then measured with a spring micrometer.
Other known techniques are described in, for example, U.S. Patent Application Publication No. 2008/0240510, entitled “Method and System for Examining a Surface;” U.S. Pat. No. 5,581,483, entitled “Measurement of Shot Peening Coverage by Correlation Analysis of Surface Line Data;” U.S. Pat. No. 5,814,722, entitled “System for Measurement of Peaks on Surfaces;” U.S. Pat. No. 4,126,036, entitled “Surface Roughness Analyzer;” and U.S. Pat. No. 3,123,999, entitled “Apparatus for Measuring Surface Roughness Peaks.”